1. Field of the Invention
The present invention relates to a GIS (Gas Insulated Switchgear) and more particularly, to a GIS with current transformers in first and second sides of circuit breaker.
2. Description of the Related Art
In general, a GIS (Gas Insulated Switchgear) includes a circuit breaker unit, a disconnecting switch unit, a ground switch unit, a potential current transforming unit, a main busbar unit, and so on, in a grounded metal tank. An inner section of the GIS is filled with Sulfur hexafluoride (SF6) gas excellent for insulation and arc extinction, and the GIS has advantages for substation miniaturization, improvement of safety and reliability, easy operation and maintenance, and so on.
As illustrated in FIGS. 1(a)-(b), a prior art GIS 100 includes a circuit breaker 110, a current transformer 120, a circuit breaker driving unit 130, a first switch 140, a second switch 150, a third switch 130, a cable head 170, a voltage transformer 180 and first and second main busbars 190a and 190b. In the GIS 100, the current transformer 120 is connected in a rear of the circuit breaker 110 and the first and second switches 140 and 150 are connected in a front of the circuit breaker 110.
FIG. 2 is a circuit diagram of the prior art gas insulated switchgear in FIG. 1.
In FIG. 2, the current transformer 120 is located between the third switch 160 and the circuit breaker 110. The first and second switches 140 and 150 are directly connected with the circuit breaker 110, thereby flowing current to the first and second main busbars 190a and 190b. 
Such a related technology is disclosed in Japanese patent publication No. 2002-165320.